Epilepsy & Seizures: Hope Through Research, Part I

Few experiences match the drama of a convulsive seizure. A person having a severe seizure may cry out, fall to
the floor unconscious, twitch or move uncontrollably, drool, or even lose
bladder control. Within minutes, the attack is over, and the person
regains consciousness but is exhausted and dazed. This is the image most
people have when they hear the word epilepsy. However, this type of
seizure � a generalized tonic-clonic seizure* � is only one kind of
epilepsy. There are many other kinds, each with a different set of
symptoms.

Epilepsy was one of the first brain
disorders to be described. It was mentioned in ancient Babylon more than
3,000 years ago. The strange behavior caused by some seizures has
contributed through the ages to many superstitions and prejudices. The
word epilepsy is derived from the Greek word for "attack." People once
thought that those with epilepsy were being visited by demons or gods.
However, in 400 B.C., the early physician Hippocrates suggested that
epilepsy was a disorder of the brain � and we now know that he was
right.

What is Epilepsy?

Epilepsy is a brain disorder in which
clusters of nerve cells, or neurons, in the brain sometimes signal
abnormally. Neurons normally generate electrochemical impulses that act on
other neurons, glands, and muscles to produce human thoughts, feelings,
and actions. In epilepsy, the normal pattern of neuronal activity becomes
disturbed, causing strange sensations, emotions, and behavior, or
sometimes convulsions, muscle spasms, and loss of consciousness.
During a seizure, neurons may fire as many as 500 times a second, much
faster than the normal rate of about 80 times a second. In some people,
this happens only occasionally; for others, it may happen up to hundreds
of times a day.

More than 2 million people in the United
States � about 1 in 100 � have experienced an unprovoked seizure or been
diagnosed with epilepsy. For about 80 percent of those diagnosed with
epilepsy, seizures can be controlled with modern medicines and surgical
techniques. However, about 20 percent of people with epilepsy will
continue to experience seizures even with the best available treatment.
Doctors call this situation intractable epilepsy. Having a seizure
does not necessarily mean that a person has epilepsy. Only when a person
has had two or more seizures is he or she considered to have
epilepsy.

Epilepsy is not contagious and is not
caused by mental illness or mental retardation. Some people with mental
retardation may experience seizures, but seizures do not necessarily mean
the person has or will develop mental impairment. Many people with
epilepsy have normal or above-average intelligence. Famous people who are
known or rumored to have had epilepsy include the Russian writer
Dostoyevsky, the philosopher Socrates, the military general Napoleon, and
the inventor of dynamite, Alfred Nobel, who established the Nobel prize.
Several Olympic medalists and other athletes also have had epilepsy.
Seizures sometimes do cause brain damage, particularly if they are severe.
However, most seizures do not seem to have a detrimental effect on the
brain. Any changes that do occur are usually subtle, and it is often
unclear whether these changes are caused by the seizures themselves or by
the underlying problem that caused the seizures.

While epilepsy cannot currently be cured,
for some people it does eventually go away. One study found that children
with idiopathic epilepsy, or epilepsy with an unknown cause, had a
68 to 92 percent chance of becoming seizure-free by 20 years after their
diagnosis. The odds of becoming seizure-free are not as good for adults,
or for children with severe epilepsy syndromes, but it is nonetheless
possible that seizures may decrease or even stop over time. This is more
likely if the epilepsy has been well-controlled by medication or if the
person has had epilepsy surgery.

What Causes Epilepsy?

Epilepsy is a disorder with many possible
causes. Anything that disturbs the normal pattern of neuron activity �
from illness to brain damage to abnormal brain development � can lead to
seizures.

Epilepsy may develop because of an
abnormality in brain wiring, an imbalance of nerve signaling chemicals
called neurotransmitters, or some combination of these factors.
Researchers believe that some people with epilepsy have an abnormally high
level of excitatory neurotransmitters that increase neuronal
activity, while others have an abnormally low level of inhibitory
neurotransmitters that decrease neuronal activity in the brain. Either
situation can result in too much neuronal activity and cause epilepsy. One
of the most-studied neurotransmitters that plays a role in epilepsy is
GABA, or gamma-aminobutyric acid, which is an inhibitory
neurotransmitter. Research on GABA has led to drugs that alter the amount
of this neurotransmitter in the brain or change how the brain responds to
it. Researchers also are studying excitatory neurotransmitters such as
glutamate.

In some cases, the brain�s attempts to
repair itself after a head injury, stroke, or other problem may
inadvertently generate abnormal nerve connections that lead to epilepsy.
Abnormalities in brain wiring that occur during brain development also may
disturb neuronal activity and lead to epilepsy.

Research has shown that the cell membrane
that surrounds each neuron plays an important role in epilepsy. Cell
membranes are crucial for neurons to generate electrical impulses. For
this reason, researchers are studying details of the membrane structure,
how molecules move in and out of membranes, and how the cell nourishes and
repairs the membrane. A disruption in any of these processes may lead to
epilepsy. Studies in animals have shown that, because the brain
continually adapts to changes in stimuli, a small change in neuronal
activity, if repeated, may eventually lead to full-blown epilepsy.
Researchers are investigating whether this phenomenon, called
kindling, may also occur in humans.

In some cases, epilepsy may result from
changes in non-neuronal brain cells called glia. These cells regulate
concentrations of chemicals in the brain that can affect neuronal
signaling.

About half of all seizures have no known
cause. However, in other cases, the seizures are clearly linked to
infection, trauma, or other identifiable problems.

Genetic Factors

Research suggests that genetic
abnormalities may be some of the most important factors contributing to
epilepsy. Some types of epilepsy have been traced to an abnormality in a
specific gene. Many other types of epilepsy tend to run in families, which
suggests that genes influence epilepsy. Some researchers estimate that
more than 500 genes could play a role in this disorder. However, it is
increasingly clear that, for many forms of epilepsy, genetic abnormalities
play only a partial role, perhaps by increasing a person�s susceptibility
to seizures that are triggered by an environmental factor.

Several types of epilepsy have now been
linked to defective genes for ion channels, the "gates" that
control the flow of ions in and out of cells and regulate neuron
signaling. Another gene, which is missing in people with progressive
myoclonus epilepsy, codes for a protein called cystatin B. This
protein regulates enzymes that break down other proteins. Another gene,
which is altered in a severe form of epilepsy called LaFora�s
disease, has been linked to a gene that helps to break down
carbohydrates.

While abnormal genes sometimes cause
epilepsy, they also may influence the disorder in subtler ways. For
example, one study showed that many people with epilepsy have an
abnormally active version of a gene that increases resistance to drugs.
This may help explain why anticonvulsant drugs do not work for some
people. Genes also may control other aspects of the body�s response to
medications and each person�ssusceptibility to seizures, or
seizure threshold. Abnormalities in the genes that control neuronal
migration � a critical step in brain development � can lead to areas of
misplaced or abnormally formed neurons, or dysplasia, in the brain
that can cause epilepsy. In some cases, genes may contribute to
development of epilepsy even in people with no family history of the
disorder. These people may have a newly developed abnormality, or
mutation, in an epilepsy-related gene.

Other
Disorders

In many cases, epilepsy develops as a
result of brain damage from other disorders. For example, brain tumors,
alcoholism, and Alzheimer�s disease frequently lead to epilepsy because
they alter the normal workings of the brain. Strokes, heart attacks, and
other conditions that deprive the brain of oxygen also can cause epilepsy
in some cases. About 32 percent of all newly developed epilepsy in elderly
people appears to be due to cerebrovascular disease, which reduces the
supply of oxygen to brain cells. Meningitis, AIDS, viral encephalitis, and
other infectious diseases can lead to epilepsy, as can hydrocephalus � a
condition in which excess fluid builds up in the brain. Epilepsy also can
result from intolerance to wheat gluten (known as celiac disease),
or from a parasitic infection of the brain called
neurocysticercosis. Seizures may stop once these disorders are
treated successfully. However, the odds of becoming seizure-free after the
primary disorder is treated are uncertain and vary depending on the type
of disorder, the brain region that is affected, and how much brain damage
occurred prior to treatment.

Epilepsy is associated with a variety of
developmental and metabolic disorders, including cerebral palsy,
neurofibromatosis, pyruvate deficiency, tuberous sclerosis,
Landau-Kleffner syndrome, and autism. Epilepsy is just one of set of
symptoms commonly found in people with these disorders.

Head Injury

In some cases, head injury can lead to
seizures or epilepsy. Safety measures such as wearing seat belts in cars
and using helmets when riding a motorcycle or playing competitive sports
can protect people from epilepsy and other problems that result from head
injury.

Prenatal Injury and Developmental Problems

The developing brain is susceptible to
many kinds of injury. Maternal infections, poor nutrition, and oxygen
deficiencies are just some of the conditions that may take a toll on the
brain of a developing baby. These conditions may lead to cerebral palsy,
which often is associated with epilepsy, or they may cause epilepsy that
is unrelated to any other disorders. About 20 percent of seizures in
children are due to cerebral palsy or other neurological abnormalities.
Abnormalities in genes that control development also may contribute to
epilepsy. Advanced brain imaging has revealed that some cases of epilepsy
that occur with no obvious cause may be associated with areas of dysplasia
in the brain that probably develop before birth.

Poisoning

Seizures can result from exposure to lead,
carbon monoxide, and many other poisons. They also can result from
exposure to street drugs and from overdoses of antidepressants and other
medications.

Seizures are often triggered by factors
such as lack of sleep, alcohol consumption, stress, or hormonal changes
associated with the menstrual cycle. These seizure triggers do not
cause epilepsy but can provoke first seizures or cause breakthrough
seizures in people who otherwise experience good seizure control with
their medication. Sleep deprivation in particular is a universal and
powerful trigger of seizures. For this reason, people with epilepsy should
make sure to get enough sleep and should try to stay on a regular sleep
schedule as much as possible. For some people, light flashing at a certain
speed or the flicker of a computer monitor can trigger a seizure; this
problem is called photosensitive epilepsy. Smoking cigarettes also
can trigger seizures. The nicotine in cigarettes acts on receptors for the
excitatory neurotransmitter acetylcholine in the brain, which increases
neuronal firing. Seizures are not triggered by sexual activity except in
very rare instances.

What Are the Different Kinds of Seizures?

Doctors have described more than 30
different types of seizures. Seizures are divided into two major
categories � partial seizures and generalized seizures.
However, there are many different types of seizures in each of these
categories.

Partial
Seizures

Partial seizures occur in just one part of
the brain. About 60 percent of people with epilepsy have partial seizures.
These seizures are frequently described by the area of the brain in which
they originate. For example, someone might be diagnosed with partial
frontal lobe seizures.

In a simple partial seizure, the
person will remain conscious but may experience unusual feelings or
sensations that can take many forms. The person may experience sudden and
unexplainable feelings of joy, anger, sadness, or nausea. He or she also
may hear, smell, taste, see, or feel things that are not real.

In a complex partial seizure, the
person has a change in or loss of consciousness. His or her consciousness
may be altered, producing a dreamlike experience. People having a complex
partial seizure may display strange, repetitious behaviors such as blinks,
twitches, mouth movements, or even walking in a circle. These repetitious
movements are called automatisms. They also may fling objects
across the room or strike out at walls or furniture as though they are
angry or afraid. These seizures usually last just a few seconds.

Some people with partial seizures,
especially complex partial seizures, may experience auras � unusual
sensations that warn of an impending seizure. These auras are actually
simple partial seizures in which the person maintains consciousness. The
symptoms an individual person has, and the progression of those symptoms,
tends to be stereotyped, or similar every time.

The symptoms of partial seizures can
easily be confused with other disorders. For instance, the dreamlike
perceptions associated with a complex partial seizure may be misdiagnosed
as migraine headaches, which also can cause a dreamlike state. The strange
behavior and sensations caused by partial seizures also can be mistaken
for symptoms of narcolepsy, fainting, or even mental illness. It may take
many tests and careful monitoring by a knowledgeable physician to tell the
difference between epilepsy and other disorders.

Generalized Seizures

Generalized seizures are a result of
abnormal neuronal activity in many parts of the brain. These seizures may
cause loss of consciousness, falls, or massive muscle spasms.

There are many kinds of generalized
seizures. In absence seizures, the person may appear to be staring
into space and/or have jerking or twitching muscles. These seizures are
sometimes referred to as petit mal seizures, which is an older
term. Tonic seizures cause stiffening of muscles of the body,
generally those in the back, legs, and arms. Clonic seizures cause
repeated jerking movements of muscles on both sides of the body.
Myoclonic seizures cause jerks or twitches of the upper body, arms,
or legs. Atonic seizures cause a loss of normal muscle tone. The
affected person will fall down or may nod his or her head involuntarily.
Tonic-clonic seizures cause a mixture of symptoms, including
stiffening of the body and repeated jerks of the arms and/or legs as well
as loss of consciousness. Tonic-clonic seizures are sometimes referred to
by an older term: grand mal seizures.

Not all seizures can be easily defined as
either partial or generalized. Some people have seizures that begin as
partial seizures but then spread to the entire brain. Other people may
have both types of seizures but with no clear pattern.

Society�s lack of understanding about the
many different types of seizures is one of the biggest problems for people
with epilepsy. People who witness a non-convulsive seizure often find it
difficult to understand that behavior which looks deliberate is not under
the person�s control. In some cases, this has led to the affected person
being arrested, sued, or placed in a mental institution. To combat these
problems, people everywhere need to understand the many different types of
seizures and how they may appear.

What Are the Different Kinds of Epilepsy?

Just as there are many different kinds of
seizures, there are many different kinds of epilepsy. Doctors have
identified hundreds of different epilepsy syndromes � disorders
characterized by a specific set of symptoms that include epilepsy. Some of
these syndromes appear to be hereditary. For other syndromes, the cause is
unknown. Epilepsy syndromes are frequently described by their symptoms or
by where in the brain they originate. People should discuss the
implications of their type of epilepsy with their doctors to understand
the full range of symptoms, the possible treatments, and the
prognosis.

People with absence epilepsy have
repeated absence seizures that cause momentary lapses of consciousness.
These seizures almost always begin in childhood or adolescence, and they
tend to run in families, suggesting that they may be at least partially
due to a defective gene or genes. Some people with absence seizures have
purposeless movements during their seizures, such as a jerking arm or
rapidly blinking eyes. Others have no noticeable symptoms except for brief
times when they are "out of it." Immediately after a seizure, the person
can resume whatever he or she was doing. However, these seizures may occur
so frequently that the person cannot concentrate in school or other
situations. Childhood absence epilepsy usually stops when the child
reaches puberty. Absence seizures usually have no lasting effect on
intelligence or other brain functions.

Psychomotor epilepsy Psychomotor epilepsy is another term
for recurrent partial seizures, especially seizures of the temporal lobe.
The term psychomotor refers to the strange sensations, emotions, and
behavior seen with these seizures.

Temporal lobe epilepsyTemporal lobe epilepsy, or TLE, is the
most common epilepsy syndrome with partial seizures. These seizures are
often associated with auras. TLE often begins in childhood. Research has
shown that repeated temporal lobe seizures can cause a brain structure
called the hippocampus to shrink over time. The hippocampus is
important for memory and learning. While it may take years of temporal
lobe seizures for measurable hippocampal damage to occur, this finding
underlines the need to treat TLE early and as effectively as
possible.

Frontal lobe epilepsy Frontal lobe epilepsy usually involves
a cluster of short seizures with a sudden onset and termination. There are
many subtypes of frontal lobe seizures. The symptoms depend on where in
the frontal lobe the seizures occur.

The symptoms of parietal lobe epilepsy
closely resemble those of other types of epilepsy. This may reflect
the fact that parietal lobe seizures tend to spread to other areas of the
brain.

There are many other types of epilepsy,
each with its own characteristic set of symptoms. Many of these, including
Lennox-Gastaut syndrome and Rasmussen�s encephalitis, begin
in childhood. Children with Lennox-Gastaut syndrome have severe epilepsy
with several different types of seizures, including atonic seizures, which
cause sudden falls and are also called drop attacks. This severe
form of epilepsy can be very difficult to treat effectively. Rasmussen�s
encephalitis is a progressive type of epilepsy in which half of the brain
shows continual inflammation. It sometimes is treated with a radical
surgical procedure called hemispherectomy (see the section on
Surgery). Some childhood epilepsy syndromes, such as childhood
absence epilepsy, tend to go into remission or stop entirely during
adolescence, whereas other syndromes such as juvenile myoclonic
epilepsy are usually present for life once they develop. Seizure
syndromes do not always appear in childhood. For example, Ramsay Hunt
syndrome type II is a rare and severe progressive type of epilepsy
that generally begins in early adulthood and leads to reduced muscle
coordination and cognitive abilities in addition to seizures.

Epilepsy syndromes that do not seem to
impair cognitive functions or development are often described as
benign. Benign epilepsy syndromes include benign infantile
encephalopathy and benign neonatal convulsions. Other
syndromes, such as early myoclonic encephalopathy, include
neurological and developmental problems. However, these problems may be
caused by underlying neurodegenerative processes rather than by the
seizures. Epilepsy syndromes in which the seizures and/or the person�s
cognitive or motor abilities get worse over time are called progressive
epilepsy.

Several types of epilepsy begin in
infancy. The most common type of infantile epilepsy is infantile
spasms, clusters of seizures that usually begin before the age of 6
months. During these seizures the infant may bend and cry out.
Anticonvulsant drugs often do not work for infantile spasms, but the
seizures can be treated with ACTH (adrenocorticotropic hormone) or
prednisone.

When Are Seizures Not Epilepsy?

While any seizure is cause for concern,
having a seizure does not by itself mean a person has epilepsy. First
seizures, febrile seizures, nonepileptic events, and eclampsia are
examples of seizures that may not be associated with epilepsy.

First Seizures

Many people have a single seizure at some
point in their lives. Often these seizures occur in reaction to anesthesia
or a strong drug, but they also may be unprovoked, meaning that they occur
without any obvious triggering factor. Unless the person has suffered
brain damage or there is a family history of epilepsy or other
neurological abnormalities, these single seizures usually are not followed
by additional seizures. One recent study that followed patients for an
average of 8 years found that only 33 percent of people have a second
seizure within 4 years after an initial seizure. People who did not have a
second seizure within that time remained seizure-free for the rest of the
study. For people who did have a second seizure, the risk of a third
seizure was about 73 percent on average by the end of 4 years.

When someone has experienced a first
seizure, the doctor will usually order an electroencephalogram,
or EEG, to determine what type of seizure the person may have
had and if there are any detectable abnormalities in the person�s brain
waves. The doctor also may order brain scans to identify abnormalities
that may be visible in the brain. These tests may help the doctor decide
whether or not to treat the person with antiepileptic drugs. In some
cases, drug treatment after the first seizure may help prevent future
seizures and epilepsy. However, the drugs also can cause detrimental side
effects, so doctors prescribe them only when they feel the benefits
outweigh the risks. Evidence suggests that it may be beneficial to begin
anticonvulsant medication once a person has had a second seizure, as the
chance of future seizures increases significantly after this
occurs.

Febrile
Seizures

Sometimes a child will have a seizure
during the course of an illness with a high fever. These seizures are
called febrile seizures (febrile is derived from the Latin
word for "fever") and can be very alarming to the parents and other
caregivers. In the past, doctors usually prescribed a course of
anticonvulsant drugs following a febrile seizure in the hope of preventing
epilepsy. However, most children who have a febrile seizure do not develop
epilepsy, and long-term use of anticonvulsant drugs in children may damage
the developing brain or cause other detrimental side effects. Experts at a
1980 consensus conference coordinated by the National Institutes of Health
concluded that preventive treatment after a febrile seizure is generally
not warranted unless certain other conditions are present: a family
history of epilepsy, signs of nervous system impairment prior to the
seizure, or a relatively prolonged or complicated seizure. The risk of
subsequent non-febrile seizures is only 2 to 3 percent unless one of these
factors is present.

Researchers have now identified several
different genes that influence the risk of febrile seizures in certain
families. Studying these genes may lead to new understanding of how
febrile seizures occur and perhaps point to ways of preventing them.

Nonepileptic Events

Sometimes people appear to have seizures,
even though their brains show no seizure activity. This type of phenomenon
has various names, including nonepileptic events and pseudoseizures. Both
of these terms essentially mean something that looks like a seizure but
isn�t one. Nonepileptic events that are psychological in origin may be
referred to as psychogenic seizures. Psychogenic seizures may indicate
dependence, a need for attention, avoidance of stressful situations, or
specific psychiatric conditions. Some people with epilepsy have
psychogenic seizures in addition to their epileptic seizures. Other people
who have psychogenic seizures do not have epilepsy at all. Psychogenic
seizures cannot be treated in the same way as epileptic seizures. Instead,
they are often treated by mental health specialists.

Other nonepileptic events may be caused by
narcolepsy, Tourette syndrome, cardiac arrhythmia, and other medical
conditions with symptoms that resemble seizures. Because symptoms of these
disorders can look very much like epileptic seizures, they are often
mistaken for epilepsy. Distinguishing between true epileptic seizures and
nonepileptic events can be very difficult and requires a thorough medical
assessment, careful monitoring, and knowledgeable health professionals.
Improvements in brain scanning and monitoring technology may improve
diagnosis of nonepileptic events in the future.

Eclampsia

Eclampsia is a life-threatening condition
that can develop in pregnant women. Its symptoms include sudden elevations
of blood pressure and seizures. Pregnant women who develop unexpected
seizures should be rushed to a hospital immediately. Eclampsia can be
treated in a hospital setting and usually does not result in additional
seizures or epilepsy once the pregnancy is over.

How is Epilepsy Diagnosed?

Doctors have developed a number of
different tests to determine whether a person has epilepsy and, if so,
what kind of seizures the person has. In some cases, people may have
symptoms that look very much like a seizure but in fact are nonepileptic
events caused by other disorders. Even doctors may not be able to tell the
difference between these disorders and epilepsy without close observation
and intensive testing.

EEG
Monitoring

An EEG records brain waves detected by
electrodes placed on the scalp. This is the most common diagnostic test
for epilepsy and can detect abnormalities in the brain�s electrical
activity. People with epilepsy frequently have changes in their normal
pattern of brain waves, even when they are not experiencing a seizure.
While this type of test can be very useful in diagnosing epilepsy, it is
not foolproof. Some people continue to show normal brain wave patterns
even after they have experienced a seizure. In other cases, the unusual
brain waves are generated deep in the brain where the EEG is unable to
detect them. Many people who do not have epilepsy also show some unusual
brain activity on an EEG. Whenever possible, an EEG should be performed
within 24 hours of a patient�s first seizure. Ideally, EEGs should be
performed while the patient is sleeping as well as when he or she is
awake, because brain activity during sleep is often quite different than
at other times.

Video monitoring is often used in
conjunction with EEG to determine the nature of a person�s seizures. It
also can be used in some cases to rule out other disorders such as cardiac
arrythmia or narcolepsy that may look like epilepsy.

In some cases, doctors may use an
experimental diagnostic technique called a magnetoencephalogram, or
MEG. MEG detects the magnetic signals generated by neurons to allow
doctors to monitor brain activity at different points in the brain over
time, revealing different brain functions. While MEG is similar in concept
to EEG, it does not require electrodes and it can detect signals from
deeper in the brain than an EEG.

Brain Scans

One of the most important ways of
diagnosing epilepsy is through the use of brain scans. The most commonly
used brain scans include CT (computed tomography), PET
(positron emission tomography) and MRI (magnetic resonance
imaging). CT and MRI scans reveal the structure of the brain, which can be
useful for identifying brain tumors, cysts, and other structural
abnormalities. PET and an adapted kind of MRI called functional MRI
(fMRI) can be used to monitor the brain�s activity and detect
abnormalities in how it works. SPECT (single photon emission
computed tomography) is a relatively new kind of brain scan that is
sometimes used to locate seizure foci in the brain. Doctors also are
experimenting with brain scans called magnetic resonance
spectroscopy (MRS) that can detect abnormalities in the brain�s
biochemical processes, and with near-infrared spectroscopy, a
technique that can detect oxygen levels in brain tissue.

Medical History

Taking a detailed medical history,
including symptoms and duration of the seizures, is still one of the best
methods available to determine if a person has epilepsy and what kind of
seizures they have. The doctor will ask questions about the seizures and
any past illnesses or other symptoms a person may have had. Since people
who have suffered a seizure often do not remember what happened,
caregivers� accounts of the seizure are vital to this
evaluation.

Blood Tests

Doctors often take blood samples for
testing, particularly when they are examining a child. These blood samples
are often screened for metabolic or genetic disorders that may be
associated with the seizures. They also may be used to check for
underlying problems such as infections, lead poisoning, anemia, and
diabetes that may be causing or triggering the seizures.

Developmental, Neurological, and Behavioral Tests

Doctors often use tests devised to measure
motor abilities, behavior, and intellectual capacity as a way to determine
how the epilepsy is affecting that person. These tests also can provide
clues about what kind of epilepsy the person has.

Can Epilepsy be Prevented?

Many cases of epilepsy can be prevented by
wearing seatbelts and bicycle helmets, putting children in car seats, and
other measures that prevent head injury and other trauma. Prescribing
medication after first or second seizures or febrile seizures also may
help prevent epilepsy in some cases. Good prenatal care, including
treatment of high blood pressure and infections during pregnancy, can
prevent brain damage in the developing baby that may lead to epilepsy and
other neurological problems later. Treating cardiovascular disease, high
blood pressure, infections, and other disorders that can affect the brain
during adulthood and aging also may prevent many cases of epilepsy.
Finally, identifying the genes for many neurological disorders can provide
opportunities for genetic screening and prenatal diagnosis that may
ultimately prevent many cases of epilepsy.

How can Epilepsy be Treated?

Accurate diagnosis of the type of epilepsy
a person has is crucial for finding an effective treatment. There are many
different ways to treat epilepsy. Currently available treatments can
control seizures at least some of the time in about 80 percent of people
with epilepsy. However, another 20 percent � about 600,000 people with
epilepsy in the United States � have intractable seizures, and another
400,000 feel they get inadequate relief from available treatments. These
statistics make it clear that improved treatments are desperately
needed.

Doctors who treat epilepsy come from many
different fields of medicine. They include neurologists, pediatricians,
pediatric neurologists, internists, and family physicians, as well as
neurosurgeons and doctors called epileptologists who specialize in
treating epilepsy. People who need specialized or intensive care for
epilepsy may be treated at large medical centers and neurology clinics at
hospitals, or by neurologists in private practice. Many epilepsy treatment
centers are associated with university hospitals that perform research in
addition to providing medical care.

Once epilepsy is diagnosed, it is
important to begin treatment as soon as possible. Research suggests that
medication and other treatments may be less successful in treating
epilepsy once seizures and their consequences become
established.

Medications

By far the most common approach to
treating epilepsy is to prescribe antiepileptic drugs. The first effective
antiepileptic drugs were bromides, introduced by an English physician
named Sir Charles Locock in 1857. He noticed that bromides had a sedative
effect and seemed to reduce seizures in some patients. More than 20
different antiepileptic drugs are now on the market, all with different
benefits and side effects. The choice of which drug to prescribe, and at
what dosage, depends on many different factors, including the type of
seizures a person has, the person�s lifestyle and age, how frequently the
seizures occur, and, for a woman, the likelihood that she will become
pregnant. People with epilepsy should follow their doctor�s advice and
share any concerns they may have regarding their medication.

Doctors seeing a patient with newly
developed epilepsy often prescribe carbamazapine, valproate, or phenytoin
first, unless the epilepsy is a type that is known to require a different
kind of treatment. For absence seizures, ethosuximide is often the primary
treatment. Other commonly prescribed drugs include clonazepam,
phenobarbital, and primidone. In recent years, a number of new drugs have
become available. These include tiagabine, lamotrigine, gabapentin,
topiramate, levetiracetam, and felbamate, as well as oxcarbazapine, a drug
that is similar to carbamazapine but has fewer side effects. These new
drugs may have advantages for many patients. Other drugs are used in
combination with one of the standard drugs or for intractable seizures
that do not respond to other medications. A few drugs, such as
fosphenytoin, are approved for use only in hospital settings to treat
specific problems such as status epilepticus (see section, "Are
There Special Risks Associated With Epilepsy?"). For people with
stereotyped recurrent severe seizures that can be easily recognized by the
person�s family, the drug diazepam is now available as a gel that can be
administered rectally by a family member. This method of drug delivery may
be able to stop prolonged seizures before they develop into status
epilepticus.

For most people with epilepsy, seizures
can be controlled with just one drug at the optimal dosage. Combining
medications usually amplifies side effects such as fatigue and decreased
appetite, so doctors usually prescribe monotherapy, or the use of
just one drug, whenever possible. Combinations of drugs are sometimes
prescribed if monotherapy fails to effectively control a patient�s
seizures.

The number of times a person needs to take
medication each day is usually determined by the drug�s half-life, or the
time it takes for half the drug dose to be metabolized or broken
down into other substances in the body. Some drugs, such as phenytoin and
phenobarbital, only need to be taken once a day, while others such as
valproate must be taken more frequently.

Most side effects of antiepileptic drugs
are relatively minor, such as fatigue, dizziness, or weight gain. However,
severe and life-threatening side effects such as allergic reactions can
occur. Epilepsy medication also may predispose people to developing
depression or psychoses. People with epilepsy should consult a doctor
immediately if they develop any kind of rash while on medication, or if
they find themselves depressed or otherwise unable to think in a rational
manner. Other danger signs that should be discussed with a doctor
immediately are extreme fatigue, staggering or other movement problems,
and slurring of words. People with epilepsy should be aware that their
epilepsy medication can interact with many other drugs in potentially
harmful ways. For this reason, people with epilepsy should always tell
doctors who treat them which medications they are taking. Women also
should know that some antiepileptic drugs can interfere with the
effectiveness of oral contraceptives, and they should discuss this
possibility with their doctors.

Since people can become more sensitive to
medications as they age, they should have their blood levels of medication
checked occasionally to see if the dose needs to be adjusted. The effects
of a particular medication also sometimes wear off over time, leading to
an increase in seizures if the dose is not adjusted. People should know
that some citrus fruit, in particular grapefruit juice, may interfere with
breakdown of many drugs. This can cause too much of the drug to build up
in their bodies, often worsening the side effects.

Tailoring the dosage of
antiepileptic drugs

When a person starts a new epilepsy drug,
it is important to tailor the dosage to achieve the best results. People�s
bodies react to medications in very different and sometimes unpredictable
ways, so it may take some time to find the right drug at the right dose to
provide optimal control of seizures while minimizing side effects. A drug
that has no effect or very bad side effects at one dose may work very well
at another dose. Doctors will usually prescribe a low dose of the new drug
initially and monitor blood levels of the drug to determine when the best
possible dose has been reached.

Generic versions are available for many
antiepileptic drugs. The chemicals in generic drugs are exactly the same
as in the brand-name drugs, but they may be absorbed or processed
differently in the body because of the way they are prepared. Therefore,
patients should always check with their doctors before switching to a
generic version of their medication.

Discontinuing medication

Some doctors will advise people with
epilepsy to discontinue their antiepileptic drugs after two years have
passed without a seizure. Others feel it is better to wait for four to
five years. Discontinuing medication should onlybe done with a
doctor�s advice and supervision. It is very important to continue taking
epilepsy medication for as long as the doctor prescribes it. People also
should ask the doctor or pharmacist ahead of time what they should do if
they miss a dose. Discontinuing medication without a doctor�s advice is
one of the major reasons people who have been seizure-free begin having
new seizures. Seizures that result from suddenly stopping medication can
be very serious and can lead to status epilepticus. Furthermore, there is
some evidence that uncontrolled seizures trigger changes in neurons that
can make it more difficult to treat the seizures in the future.

The chance that a person will eventually
be able to discontinue medication varies depending on the person�s age and
his or her type of epilepsy. More than half of children who go into
remission with medication can eventually stop their medication without
having new seizures. One study showed that 68 percent of adults who had
been seizure-free for 2 years before stopping medication were able to do
so without having more seizures and 75 percent could successfully
discontinue medication if they had been seizure-free for 3 years. However,
the odds of successfully stopping medication are not as good for people
with a family history of epilepsy, those who need multiple medications,
those with partial seizures, and those who continue to have abnormal EEG
results while on medication.

Surgery

When seizures cannot be adequately
controlled by medications, doctors may recommend that the person be
evaluated for surgery. Most surgery for epilepsy is performed by teams of
doctors at medical centers. To decide if a person may benefit from
surgery, doctors consider the type or types of seizures he or she has.
They also take into account the brain region involved and how important
that region is for everyday behavior. Surgeons usually avoid operating in
areas of the brain that are necessary for speech, language, hearing, or
other important abilities. Doctors may perform tests such as a WADA test
(administration of the drug amobarbitol into the carotid artery) to find
areas of the brain that control speech and memory. They often monitor the
patient intensively prior to surgery in order to pinpoint the exact
location in the brain where seizures begin. They also may use implanted
electrodes to record brain activity from the surface of the brain. This
yields better information than an external EEG.

A 1990 National Institutes of Health
consensus conference on surgery for epilepsy concluded that there are
three broad categories of epilepsy that can be treated successfully with
surgery. These include partial seizures, seizures that begin as partial
seizures before spreading to the rest of the brain, and unilateral
multifocal epilepsy with infantile hemiplegia (such as Rasmussen�s
encephalitis). Doctors generally recommend surgery only after patients
have tried two or three different medications without success, or if there
is an identifiable brain lesion�a damaged or abnormally functioning
area�believed to cause the seizures.

If a person is considered a good candidate
for surgery and has seizures that cannot be controlled with available
medication, experts generally agree that surgery should be performed as
early as possible. It can be difficult for a person who has had years of
seizures to fully re-adapt to a seizure-free life if the surgery is
successful. The person may never have had an opportunity to develop
independence and he or she may have had difficulties with school and work
that could have been avoided with earlier treatment. Surgery should always
be performed with support from rehabilitation specialists and counselors
who can help the person deal with the many psychological, social, and
employment issues he or she may face.

While surgery can significantly reduce or
even halt seizures for some people, it is important to remember that any
kind of surgery carries some amount of risk (usually small). Surgery for
epilepsy does not always successfully reduce seizures and it can result in
cognitive or personality changes, even in people who are excellent
candidates for surgery. Patients should ask their surgeon about his or her
experience, success rates, and complication rates with the procedure they
are considering.

Even when surgery completely ends a
person�s seizures, it is important to continue taking seizure medication
for some time to give the brain time to re-adapt. Doctors generally
recommend medication for 2 years after a successful operation to avoid new
seizures.

Surgery to treat underlying
conditions

In cases where seizures are caused by a
brain tumor, hydrocephalus, or other conditions that can be treated with
surgery, doctors may operate to treat these underlying conditions. In many
cases, once the underlying condition is successfully treated, a person�s
seizures will stop as well.

Surgery to remove a seizure
focus

The most common type of surgery for
epilepsy is removal of a seizure focus, or small area of the brain
where seizures originate. This type of surgery, which doctors may refer to
as a lobectomy or lesionectomy, is appropriate only for
partial seizures that originate in just one area of the brain. In general,
people have a better chance of becoming seizure-free after surgery if they
have a small, well-defined seizure focus. Lobectomies have a 55-70 percent
success rate when the type of epilepsy and the seizure focus is
well-defined. The most common type of lobectomy is a temporal lobe
resection, which is performed for people with temporal lobe epilepsy.
Temporal lobe resection leads to a significant reduction or complete
cessation of seizures about 70 - 90 percent of the time.

Multiple subpial
transection

When seizures originate in part of the
brain that cannot be removed, surgeons may perform a procedure called a
multiple subpial transection. In this type of operation, which was
first described in 1989, surgeons make a series of cuts that are designed
to prevent seizures from spreading into other parts of the brain while
leaving the person�s normal abilities intact. About 70 percent of patients
who undergo a multiple subpial transection have satisfactory improvement
in seizure control.

Corpus callosotomy

Corpus callosotomy, Corpus callosotomy, or severing the
network of neural connections between the right and left halves, or
hemispheres, of the brain, is done primarily in children with
severe seizures that start in one half of the brain and spread to the
other side. Corpus callosotomy can end drop attacks and other generalized
seizures. However, the procedure does not stop seizures in the side of the
brain where they originate, and these partial seizures may even increase
after surgery.

Hemispherectomy

This procedure, which removes half of the
brain�s cortex, or outer layer, is used only for children who have
Rasmussen�s encephalitis or other severe damage to one brain hemisphere
and who also have seizures that do not respond well to medication. While
this type of surgery is very radical and is performed only as a last
resort, children often recover very well from the procedure, and their
seizures usually are greatly reduced or may cease altogether. With intense
rehabilitation, they often recover nearly normal abilities. Since the
chance of a full recovery is best in young children, hemispherectomy
should be performed as early in a child�s life as possible. It is almost
never performed in children older than 13.

Devices

The vagus nerve stimulator was approved by
the U.S. Food and Drug Administration (FDA) in 1997 for use in people with
seizures that are not well-controlled by medication. The vagus nerve
stimulator is a battery-powered device that is surgically implanted under
the skin of the chest, much like a pacemaker, and is attached to the vagus
nerve in the lower neck. This device delivers short bursts of electrical
energy to the brain via the vagus nerve. On average, this stimulation
reduces seizures by about 20-40 percent. Patients usually cannot stop
taking epilepsy medication because of the stimulator, but they often
experience fewer seizures and they may be able to reduce the dose of their
medication. Side effects of the vagus nerve stimulator are generally mild,
but may include ear pain, a sore throat, or nausea. Adjusting the amount
of stimulation can usually eliminate these side effects. The batteries in
the vagus nerve stimulator need to be replaced about once every 5 years;
this requires a minor operation that can usually be performed as an
outpatient procedure.

Several new devices may become available
for epilepsy in the future. Researchers are studying whether
transcranial magnetic stimulation, a procedure which uses a strong
magnet held outside the head to influence brain activity, may reduce
seizures. They also hope to develop implantable devices that can deliver
drugs to specific parts of the brain.

Diet

Studies have shown that, in some cases,
children may experience fewer seizures if they maintain a strict diet rich
in fats and low in carbohydrates. This unusual diet, called the
ketogenic diet, causes the body to break down fats instead of
carbohydrates to survive. This condition is called ketosis. One study of
150 children whose seizures were poorly controlled by medication found
that about one-fourth of the children had a 90 percent or better decrease
in seizures with the ketogenic diet, and another half of the group had a
50 percent or better decrease in their seizures. Moreover, some children
can discontinue the ketogenic diet after several years and remain
seizure-free. The ketogenic diet is not easy to maintain, as it requires
strict adherence to an unusual and limited range of foods. Possible side
effects include retarded growth due to nutritional deficiency and a
buildup of uric acid in the blood, which can lead to kidney stones. People
who try the ketogenic diet should seek the guidance of a dietician to
ensure that it does not lead to serious nutritional deficiency.

Researchers are not sure how ketosis
inhibits seizures. One study showed that a byproduct of ketosis called
beta-hydroxybutyrate (BHB) inhibits seizures in animals. If BHB also works
in humans, researchers may eventually be able to develop drugs that mimic
the seizure-inhibiting effects of the ketogenic diet.

Other Treatment Strategies

Researchers are studying whether
biofeedback � a strategy in which individuals learn to control their own
brain waves � may be useful in controlling seizures. However, this type of
therapy is controversial and most studies have shown discouraging results.
Taking large doses of vitamins generally does not help a person�s seizures
and may even be harmful in some cases. However, a good diet and some
vitamin supplements, particularly folic acid, may help reduce some birth
defects and medication-related nutritional deficiencies. Use of
non-vitamin supplements such as melatonin is controversial and can be
risky. One study showed that melatonin may reduce seizures in some
children, while another found that the risk of seizures increased
measurably with melatonin. Most non-vitamin supplements such as those
found in health food stores are not regulated by the FDA, so their true
effects and their interactions with other drugs are largely
unknown.

Source: National Institute of Neurological Disorders and Stroke, National Institutes of Health